Defining the function of tubulin post-translational modifications in female meiosis

The National Institute of Child Health and Human Development awarded Yale University $100,228 on December 1, 2026, under the Child Health and Human Development Extramural Research program (CFDA 93.865) to define the function of tubulin post-translational modifications in female meiosis.

The research investigates microtubule organization and chromosome segregation mechanisms in oocytes to probe the molecular origins of egg aneuploidy. The recipient will use mouse oocytes as a model of mammalian meiosis, employing quantitative immunofluorescence microscopy and Western blotting to characterize the tubulin post-translational modification (PTM) profile of oocytes. Using rapid protein degradation tools, the recipient will disrupt PTMs and combine that approach with high-resolution and super-resolution live and immunofluorescence microscopy to identify tubulin PTMs required for cytoplasmic microtubule organization and dynamics, meiotic spindle assembly, and chromosome segregation. Mechanistic experiments will probe how tubulin PTM disruption impacts microtubule function and drives chromosome segregation errors.

Yale University serves as the recipient, with place of performance in New Haven, Connecticut. The period of performance runs from December 1, 2026, through June 30, 2029.

Abstract

Female meiosis generates fertilizable eggs from progenitor oocytes. Chromosome segregation in oocytes is driven by a microtubule-based spindle machinery. For poorly understood reasons, oocytes are highly predisposed to chromosome segregation errors that lead to aneuploidies, with these chromosomal abnormalities accounting for up to 35% of miscarriages. Oocyte aneuploidy rates increase dramatically with advancing maternal age, which severely impacts pregnancy outcomes. This proposal will investigate microtubule organization and chromosome segregation mechanisms in oocytes and probe the molecular origins of EGG aneuploidy. The microtubule cytoskeleton is built from tubulin heterodimers that are subject to various post- translational modifications (PTMS). Tubulin PTMS are postulated to control microtubule diversity and function in many cell types. However, their role in oocyte meiosis and whether tubulin PTM dysfunction underlies high chromosome segregation error rates in female meiosis is unknown. In this research, I will use mouse oocytes, a well-established model of mammalian oocyte meiosis, to address this fundamental conceptual GAP in reproductive biology. I will achieve this by pursuing two specific aims. In aim 1, I will define the tubulin PTM profile of oocytes using quantitative immunofluorescence microscopy and western blotting analyses. To study tubulin PTM function in oocytes, I will disrupt PTMS using innovative rapid protein degradation tools. By combining this approach with high-resolution and super-resolution live and immunofluorescence microscopy of microtubules, chromosomes, and cytoskeletal proteins, I will identify tubulin PTMS that are required for organization and dynamics of cytoplasmic microtubules, meiotic spindle assembly, and chromosome segregation. In further mechanistic experiments, I will probe how tubulin PTM disruption impacts microtubule- associated proteins that drive microtubule organization and chromosome segregation. In aim 2, I will investigate how tubulin PTM dysfunction contributes to age-related oocyte aneuploidy. Recent work from our lab and others revealed that cytoskeletal dysfunction contributes to age-related aneuploidy. I will examine whether dysregulated microtubule modification underlies cytoskeletal dysfunction at advanced reproductive ages by taking a candidate-based approach to identify tubulin modifying enzymes that are altered in aged oocytes. By combining experimental approaches from aim 1 with enzyme overexpression approaches, I will override microtubule modifications and ask whether dysregulation of identified PTM candidates is sufficient to induce aging-like chromosomal phenotypes in young oocytes. Conversely, I will test whether targeted manipulation of tubulin PTMS can rescue chromosome segregation fidelity in aged oocytes. Integrated approaches from these two aims are likely to reveal key post-translational modifications of tubulin proteins that govern oocyte-specific cytoskeletal structures and chromosome segregation mechanisms. Uncovering new root causes of high aneuploidy rates in this research could accelerate new therapeutics against human infertility and genetic disorders.